Estimated glomerular filtration rate in clinical practice: Consensus positioning of the Brazilian Society of Nephrology (SBN) and Brazilian Society of Clinical Pathology and Laboratory Medicine (SBPC/ML).

Chronic kidney disease (CKD) represents one of today's main public health problems. Serum creatinine measurement and estimation of the glomerular filtration rate (GFR) are the main tools for evaluating renal function. There are several equations to estimate GFR, and CKD-EPI equation (Chronic Kidney Disease - Epidemiology) is the most recommended one. There are still some controversies regarding serum creatinine measurement and GFR estimation, since several factors can interfere in this process. An important recent change was the removal of the correction for race from the equations for estimating GFR, which overestimated kidney function, and consequently delayed the implementation of treatments such as dialysis and kidney transplantation. In this consensus document from the Brazilian Societies of Nephrology and Clinical Pathology and Laboratory Medicine, the main concepts related to the assessment of renal function are reviewed, as well as possible existing controversies and recommendations for estimating GFR in clinical practice.

Temporal validation of a Generalized Additive2 Model (GA2M) to assess the risk of Chronic Kidney Disease (CKD).

OBJECTIVE: To assess the temporal validity of a model predicting the risk of Chronic Kidney Disease (CKD) using Generalized Additive2 Models (GA2M). MATERIALS: We adopted the Italian Health Search Database (HSD) with which the original algorithm was developed and validated by comparing different machine learnings models. METHODS: We selected all patients aged >=15 being active in HSD in 2019. They were followed up until December 2022 so being updated with three years of data collection. Those with prior diagnosis of CKD were excluded. A GA2M-based algorithm for CKD prediction was applied to this cohort in order to compare observed and predicted risk. Area Under Curve (AUC) and Average Precision (AP) were calculated. RESULTS: We obtained an AUC and AP equal to 88% and 30%, respectively. DISCUSSION: The prediction accuracy of the algorithm was largely consistent with that obtained in our prior work which was based on a different time-window for data collection. We therefore underlined and demonstrated the relevance of temporal validation for this prediction tool. CONCLUSION: The GA2M confirmed its high accuracy in prediction of CKD. As such, the respective patient- and population-based informatic tools might be implemented in primary care.

Cardiogenic shock and chronic kidney disease: Dangerous liaisons.

BACKGROUND: Chronic kidney disease (CKD) is one of the leading causes of death worldwide, closely interrelated with cardiovascular diseases, ultimately leading to the failure of both organs - the so-called "cardiorenal syndrome". Despite this burden, data related to cardiogenic shock outcomes in CKD patients are scarce. METHODS: FRENSHOCK (NCT02703038) was a prospective registry involving 772 patients with cardiogenic shock from 49 centres. One-year outcomes (rehospitalization, death, heart transplantation, ventricular assist device) were analysed according to history of CKD at admission and were adjusted on independent predictive factors. RESULTS: CKD was present in 164 of 771 patients (21.3%) with cardiogenic shock; these patients were older (72.7 vs. 63.9years) and had more comorbidities than those without CKD. CKD was associated with a higher rate of all-cause mortality at 1month (36.6% vs. 23.2%; hazard ratio 1.39, 95% confidence interval 1.01-1.9; P=0.04) and 1year (62.8% vs. 40.5%, hazard ratio 1.39, 95% confidence interval 1.09-1.77; P<0.01). Patients with CKD were less likely to be treated with norepinephrine/epinephrine or undergo invasive ventilation or receive mechanical circulatory support, but were more likely to receive renal replacement therapy (RRT). RRT was associated with a higher risk of all-cause death at 1month and 1year regardless of baseline CKD status. CONCLUSIONS: Cardiogenic shock and CKD are frequent "cross-talking" conditions with limited therapeutic options, resulting in higher rates of death at 1month and 1year. RRT is a strong predictor of death, regardless of preexisting CKD. Multidisciplinary teams involving cardiac and kidney physicians are required to provide integrated care for patients with failure of both organs.

[InspeCKD - Analysis of the use of diagnostics in patients at high risk for chronic kidney disease in German general practitioner (GP) practices]. / InspeCKD - Analyse zur Nutzung von Labordiagnostik im Kontext der chronischen Nierenerkrankung : Daten von Risikopatientinnen und -patienten in deutschen Hausarztpraxen.

BACKGROUND: Despite the high prevalence of chronic kidney disease (CKD) in Germany, only a small proportion of patients are currently diagnosed with CKD. Patients with hypertension, diabetes mellitus, and/or cardiovascular disease have a significantly increased risk of developing CKD and rapid disease progression and should therefore be screened and monitored in accordance with the guidelines. OBJECTIVES: The aim of this retrospective, cross-sectional study was to gain insights into appropriate diagnosis of patients at risk for CKD in German general practitioner practices. METHOD: For the analysis of the use of CKD-relevant diagnostics, electronic patient records from German general practitioner practices were analyzed. Adults with hypertension and/or diabetes mellitus and/or cardiovascular disease with a documented observation period of at least one year were included in the study. RESULTS: Data from a total of 448,837 patients from 1244 general practitioner practices were analyzed. 75.8% of patients had hypertension, 35.1% had cardiovascular disease, and 32.4% had diabetes mellitus. During a mean observation period of 1.7 years, serum creatinine was assessed at least once in 45.5% of patients. A urine dipstick test for albuminuria was performed in 7.9% of patients and in 0.4% of patients, urine albumin-to-creatine ratio (UACR) was measured. Laboratory diagnostics were initiated a little more frequently in high-risk patients compared to the overall cohort. CONCLUSIONS: The study highlights that despite known risk factors, guideline compliant CKD screening is rarely performed in German general practitioner practices, which implicates the need to increase the awareness of early diagnosis of CKD in patients at risk.

Effect modification of polypharmacy on incident frailty by chronic kidney disease in older adults.

BACKGROUND: Frailty and polypharmacy are common conditions in older adults, especially in those with chronic kidney disease (CKD). Therefore, we analyzed the association of polypharmacy and incident frailty and the effect modification by CKD in very old adults. METHODS: In non-frail individuals within the Berlin Initiative (cohort) Study, polypharmacy (≥ 5 medications) was assessed according to multiple definitions based on the number of regular and on demand prescription and over the counter drugs, as well as vitamins and supplements. CKD was defined as an estimated glomerular filtration rate < 60 mL/min/1.73m2 and/or an albumin-creatinine ratio ≥ 30 mg/g. Incident frailty was assessed at follow-up using Fried criteria. Logistic regression was applied to assess (1) the association of different polypharmacy definitions with incident frailty and (2) effect modification by CKD. RESULTS: In this cohort study, out of 757 non-frail participants (mean age 82.9 years, 52% female, 74% CKD), 298 (39%) participants reported polypharmacy. Over the observation period of 2.1 years, 105 became frail. Individuals with polypharmacy had 1.96 adjusted odds (95% confidence interval (CI): 1.20-3.19) of becoming frail compared to participants without polypharmacy. The effect of polypharmacy on incident frailty was modified by CKD on the additive scale (relative excess risk due to interaction: 1.56; 95% CI 0.01-3.12). CONCLUSIONS: This study demonstrates an association of polypharmacy and incident frailty and suggests strong evidence for an effect modification of CKD on polypharmacy and incident frailty. Revision of prescriptions could be a target strategy to prevent frailty occurrence, especially in older adults with CKD.

Assessment and Risk Prediction of Chronic Kidney Disease and Kidney Fibrosis Using Non-Invasive Biomarkers.

Effective management of chronic kidney disease (CKD), a major health problem worldwide, requires accurate and timely diagnosis, prognosis of progression, assessment of therapeutic efficacy, and, ideally, prediction of drug response. Multiple biomarkers and algorithms for evaluating specific aspects of CKD have been proposed in the literature, many of which are based on a small number of samples. Based on the evidence presented in relevant studies, a comprehensive overview of the different biomarkers applicable for clinical implementation is lacking. This review aims to compile information on the non-invasive diagnostic, prognostic, and predictive biomarkers currently available for the management of CKD and provide guidance on the application of these biomarkers. We specifically focus on biomarkers that have demonstrated added value in prospective studies or those based on prospectively collected samples including at least 100 subjects. Published data demonstrate that several valid non-invasive biomarkers of potential value in the management of CKD are currently available.

Frail hypertensive older adults with prediabetes and chronic kidney disease: insights on organ damage and cognitive performance - preliminary results from the CARYATID study.

BACKGROUND: Hypertension and chronic kidney disease (CKD) pose significant public health challenges, sharing intertwined pathophysiological mechanisms. Prediabetes is recognized as a precursor to diabetes and is often accompanied by cardiovascular comorbidities such as hypertension, elevating the risk of pre-frailty and frailty. Albuminuria is a hallmark of organ damage in hypertension amplifying the risk of pre-frailty, frailty, and cognitive decline in older adults. We explored the association between albuminuria and cognitive impairment in frail older adults with prediabetes and CKD, assessing cognitive levels based on estimated glomerular filtration rate (eGFR). METHODS: We conducted a study involving consecutive frail older patients with hypertension recruited from March 2021 to March 2023 at the ASL (local health unit of the Italian Ministry of Health) of Avellino, Italy, followed up after three months. Inclusion criteria comprised age over 65 years, prior diagnosis of hypertension without secondary causes, prediabetes, frailty status, Montreal Cognitive Assessment (MoCA) score < 26, and CKD with eGFR > 15 ml/min. RESULTS: 237 patients completed the study. We examined the association between albuminuria and MoCA Score, revealing a significant inverse correlation (r: 0.8846; p < 0.0001). Subsequently, we compared MoCA Score based on eGFR, observing a significant difference (p < 0.0001). These findings were further supported by a multivariable regression analysis, with albuminuria as the dependent variable. CONCLUSIONS: Our study represents the pioneering effort to establish a significant correlation between albuminuria and eGFR with cognitive function in frail hypertensive older adults afflicted with prediabetes and CKD.

Determinants of early chronic kidney disease in patients with recently diagnosed type 2 diabetes mellitus: a retrospective study from the Taiwan Diabetes Registry.

BACKGROUND: We tried to identify the risk factor associate with early chronic kidney disease (CKD) in recently diagnosed type 2 diabetes mellitus patients by utilizing real-world data from Taiwan Diabetes Registry. MATERIALS AND METHODS: Patients with type 2 diabetes mellitus recently diagnosed within 1 year. We divided the study participants into control group and early CKD group. Early CKD was defined as either CKD stage G1 with albuminuria, CKD stage G2 with albuminuria, or CKD stage G3a regardless of albuminuria (Urine-albumin to creatinine ratio (UACR) ≥ 3 mg/mmol). Control group was defined as CKD G1 or CKD G2 without albuminuria. Logistic regression analyses were used to compare differences in clinical characteristics between the subgroups. Linear regression models were employed to examine the factors predicting estimated glomerular filtration rate (eGFR) and UACR. RESULTS: Total 2217 patients with recently diagnosed type 2 diabetes mellitus were included. 1545 patients were assigned to control group and 618 patients were assigned to the early CKD group. Age (odds ratio (OR) 1.215, 95% confidence interval [CI] 1.122-1.316), systolic blood pressure (OR 1.203, 95% CI 1.117-1.296), glycated hemoglobin (OR 1.074, 95% CI 1.023-1.129) and triglyceride (OR 2.18, 95% CI 1.485-3.199) were found to be significant risk factors. Further, presence of bidirectional association between UACR and eGFR was found. CONCLUSIONS: We reported factors associated with early CKD in recently diagnosed type 2 diabetes mellitus patients. Variables that associated with eGFR and UACR were identified respectively, included a mutual influence between UACR and eGFR.

Comprehensive geriatric assessment of older patients with renal disease: a cross-sectional survey.

Multidimensional health function impairments are common in older patients with chronic kidney disease (CKD). The purpose of this study was to explore whether the risk or severity of geriatric syndrome increased with a decline in renal function. This survey was conducted for CKD patients aged ≥ 60 years and hospitalized at West China Hospital of Sichuan University (Center of Gerontology and Geriatrics, Nephrology, and Endocrinology) and Chengdu Kangfu Kidney Disease Hospital from September 01, 2013 to June 30, 2014. Patients underwent multidimensional individualized assessments by trained doctors. Logistic regression analysis found that the risk of assisted walking (P = 0.001) and urinary incontinence (P = 0.039) increased with a decline in renal function. Regression analysis revealed that the scores of activities of daily living (P = 0.024), nutritional status (P = 0.000), total social support (P = 0.014), and objective support (P = 0.000) decreased with a decline in renal function.

Clinical Implications of Estimating Glomerular Filtration Rate with Different Equations in Heart Failure Patients with Preserved Ejection Fraction.

INTRODUCTION: The prognostic values of estimated glomerular filtration rate (eGFR) calculated by different formulas have not been adequately compared in patients with heart failure with preserved ejection fraction (HFpEF). AIM: We compared the predictive values of serum creatinine-based eGFRs calculated by the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) 2009 equation, Modification of Diet in Renal Disease Study (MDRD) formula, and full-age-spectrum creatinine (FAS Cr) equation in 1751 HFpEF patients. METHODS: The area under the receiver-operating characteristic curve (AUC), integrated discrimination improvement (IDI) and net reclassification improvement (NRI) were employed. RESULTS: eGFR values were lowest calculated with FAS Cr equation (p < 0.001). When patients were classified into 4 subgroups (eGFR ≥ 90, 89-60, 59-30, and  < 30 ml/min/1.73 m2) or only 2 subgroups (≥ 60 or  < 60 ml/min/1.73 m2), the 3 formulas correlated significantly, with the best correlation found between the MDRD and CKD-EPI formulas (kappa = 0.871 and 0.963, respectively). The 3 formulas conveyed independent prognostic information. After adjusting for potential cofounders, risk prediction for all-cause mortality was more accurate (p = 0.001) using the CKD-EPI equation than MDRD formula as assessed by AUC. Compared with MDRD formula, CKD-EPI equation exhibited superior predictive ability assessed by IDI and NRI of 0.32% (p < 0.001)/10.4% (p = 0.010) for primary endpoint and 0.37% (p = 0.010)/10.8% (p = 0.010) for HF hospitalization. The risk prediction for deterioration of renal function was more accurate (p ≤ 0.040) using the CKD-EPI equation than FAS Cr equation as assessed by AUC, IDI, and NRI. CONCLUSION: The CKD-EPI formula might be the preferred creatinine-based equation in clinical risk stratification in HFpEF patients.

Exploration of Diagnostic Markers Associated with Inflammation in Chronic Kidney Disease Based on WGCNA and Machine Learning.

Chronic kidney disease (CKD) is a common disorder related to inflammatory pathways; its effective management remains limited. This study aimed to use bioinformatics analysis to find diagnostic markers that might be therapeutic targets for CKD. CKD microarray datasets were screened from the GEO database and the differentially expressed genes (DEGs) in CKD dataset GSE98603 were analyzed. Gene set variation analysis (GSVA) was used to explore the activity scores of the inflammatory pathways and samples. Algorithms such as weighted gene co-expression network analysis (WGCNA) and Lasso were used to screen CKD diagnostic markers related to inflammation. Then functional enrichment analysis of inflammation-related DEGs was performed. ROC curves were conducted to examine the diagnostic value of inflammation-related hub-genes. Lastly, quantitative real-time PCR further verified the prediction of bioinformatics. A total of 71 inflammation-related DEGs were obtained, of which 5 were hub genes. Enrichment analysis showed that these genes were significantly enriched in inflammation-related pathways (NF-κB, JAK-STAT, and MAPK signaling pathways). ROC curves showed that the 5 CKD diagnostic markers (TIGD7, ACTA2, ACTG2, MAP4K4, and HOXA11) also exhibited good diagnostic value. In addition, TIGD7, ACTA2, ACTG2, and HOXA11 expression was downregulated while MAP4K4 expression was upregulated in LPS-induced HK-2 cells. The present study identified TIGD7, ACTA2, ACTG2, MAP4K4, and HOXA11 as reliable CKD diagnostic markers, thereby providing a basis for further understanding of CKD in clinical treatments.

UroAngel: a single-kidney function prediction system based on computed tomography urography using deep learning.

BACKGROUND: Accurate estimation of the glomerular filtration rate (GFR) is clinically crucial for determining the status of obstruction, developing treatment strategies, and predicting prognosis in obstructive nephropathy (ON). We aimed to develop a deep learning-based system, named UroAngel, for non-invasive and convenient prediction of single-kidney function level. METHODS: We retrospectively collected computed tomography urography (CTU) images and emission computed tomography diagnostic reports of 520 ON patients. A 3D U-Net model was used to segment the renal parenchyma, and a logistic regression multi-classification model was used to predict renal function level. We compared the predictive performance of UroAngel with the Modification of Diet in Renal Disease (MDRD), Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations, and two expert radiologists in an additional 40 ON patients to validate clinical effectiveness. RESULTS: UroAngel based on 3D U-Net convolutional neural network could segment the renal cortex accurately, with a Dice similarity coefficient of 0.861. Using the segmented renal cortex to predict renal function stage had high performance with an accuracy of 0.918, outperforming MDRD and CKD-EPI and two radiologists. CONCLUSIONS: We proposed an automated 3D U-Net-based analysis system for direct prediction of single-kidney function stage from CTU images. UroAngel could accurately predict single-kidney function in ON patients, providing a novel, reliable, convenient, and non-invasive method.

Development and validation of a race-agnostic computable phenotype for kidney health in adult hospitalized patients.

Standard race adjustments for estimating glomerular filtration rate (GFR) and reference creatinine can yield a lower acute kidney injury (AKI) and chronic kidney disease (CKD) prevalence among African American patients than non-race adjusted estimates. We developed two race-agnostic computable phenotypes that assess kidney health among 139,152 subjects admitted to the University of Florida Health between 1/2012-8/2019 by removing the race modifier from the estimated GFR and estimated creatinine formula used by the race-adjusted algorithm (race-agnostic algorithm 1) and by utilizing 2021 CKD-EPI refit without race formula (race-agnostic algorithm 2) for calculations of the estimated GFR and estimated creatinine. We compared results using these algorithms to the race-adjusted algorithm in African American patients. Using clinical adjudication, we validated race-agnostic computable phenotypes developed for preadmission CKD and AKI presence on 300 cases. Race adjustment reclassified 2,113 (8%) to no CKD and 7,901 (29%) to a less severe CKD stage compared to race-agnostic algorithm 1 and reclassified 1,208 (5%) to no CKD and 4,606 (18%) to a less severe CKD stage compared to race-agnostic algorithm 2. Of 12,451 AKI encounters based on race-agnostic algorithm 1, race adjustment reclassified 591 to No AKI and 305 to a less severe AKI stage. Of 12,251 AKI encounters based on race-agnostic algorithm 2, race adjustment reclassified 382 to No AKI and 196 (1.6%) to a less severe AKI stage. The phenotyping algorithm based on refit without race formula performed well in identifying patients with CKD and AKI with a sensitivity of 100% (95% confidence interval [CI] 97%-100%) and 99% (95% CI 97%-100%) and a specificity of 88% (95% CI 82%-93%) and 98% (95% CI 93%-100%), respectively. Race-agnostic algorithms identified substantial proportions of additional patients with CKD and AKI compared to race-adjusted algorithm in African American patients. The phenotyping algorithm is promising in identifying patients with kidney disease and improving clinical decision-making.

Spurious Hyperphosphatemia in a Patient with Chronic Kidney Disease - a Rare Case of Alteplase Contamination.

Spurious hyperphosphatemia, a rare occurrence, typically arises from substances in a patient's blood interfering with the colorimetric method for serum phosphate measurement. We present a case of factitious hyperphosphatemia caused by alteplase-contaminated blood samples in an 88-year-old CKD patient on hemodialysis, leading to misleadingly high phosphorus levels. Thorough investigations ruled out other etiologies, highlighting the necessity of stringent adherence to blood collection protocols to prevent sample contamination and avert erroneous laboratory results. This unique cause of hyperphosphatemia should be considered in the differential diagnosis when encountering unexplained elevations in phosphorus levels, particularly in the context of normal blood calcium levels.

External validation of a minimal-resource model to predict reduced estimated glomerular filtration rate in people with type 2 diabetes without diagnosis of chronic kidney disease in Mexico: a comparison between country-level and regional performance.

Background: Patients with type 2 diabetes are at an increased risk of chronic kidney disease (CKD) hence it is recommended that they receive annual CKD screening. The huge burden of diabetes in Mexico and limited screening resource mean that CKD screening is underperformed. Consequently, patients often have a late diagnosis of CKD. A regional minimal-resource model to support risk-tailored CKD screening in patients with type 2 diabetes has been developed and globally validated. However, population heath and care services between countries within a region are expected to differ. The aim of this study was to evaluate the performance of the model within Mexico and compare this with the performance demonstrated within the Americas in the global validation. Methods: We performed a retrospective observational study with data from primary care (Clinic Specialized in Diabetes Management in Mexico City), tertiary care (Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán) and the Mexican national survey of health and nutrition (ENSANUT-MC 2016). We applied the minimal-resource model across the datasets and evaluated model performance metrics, with the primary interest in the sensitivity and increase in the positive predictive value (PPV) compared to a screen-everyone approach. Results: The model was evaluated on 2510 patients from Mexico (primary care: 1358, tertiary care: 735, ENSANUT-MC: 417). Across the Mexico data, the sensitivity was 0.730 (95% CI: 0.689 - 0.779) and the relative increase in PPV was 61.0% (95% CI: 52.1% - 70.8%). These were not statistically different to the regional performance metrics for the Americas (sensitivity: p=0.964; relative improvement: p=0.132), however considerable variability was observed across the data sources. Conclusion: The minimal-resource model performs consistently in a representative Mexican population sample compared with the Americas regional performance. In primary care settings where screening is underperformed and access to laboratory testing is limited, the model can act as a risk-tailored CKD screening solution, directing screening resources to patients who are at highest risk.

Chronic kidney disease and cognitive performance: NHANES 2011-2014.

PURPOSE: Previous studies suggest an association between chronic kidney disease (CKD) and cognitive impairment. The purpose of this study was to explore the association between the diverse stages of CKD and the cognitive performance of elderly American adults. METHODS: Data from the National Health and Nutrition Examination Survey (NHANES) 2011-2014 were used. Multivariate adjusted logistic regression, subgroup analysis, and the restricted cubic spline model were used to assess the associations of CKD stage and estimated glomerular filtration rate (eGFR) with cognitive performance. The measures used to evaluate cognitive function included the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) test, the Animal Fluency test, and the Digit Symbol Substitution test (DSST). RESULTS: This study included 2234 participants aged ≥ 60 years. According to the fully adjusted model, stages 3-5 CKD were significantly associated with the CERAD test score (OR = 0.70, 95% CI [0.51, 0.97], p = 0.033), the Animal Fluency test score (OR = 0.64, 95% CI [0.48, 0.85], p = 0.005), and the DSST score (OR = 0.60, 95% CI [0.41, 0.88], p = 0.013). In addition, the incidence of poor cognitive function increased with decreasing eGFR, especially for individuals with low and moderate eGFRs. Both the DSST score (p nonlinearity < 0.0001) and the Animal Fluency test score (p nonlinearity = 0.0001) had nonlinear dose-response relationships with the eGFR. However, a linear relationship was shown between the eGFR and CERAD test score (p nonlinearity = 0.073). CONCLUSIONS: CKD, especially stages3-5 CKD, was significantly associated with poor cognitive performance in terms of executive function, learning, processing speed, concentration, and working memory ability. All adults with CKD should be screened for cognitive impairment.